Flat panel display (FPD) technology is one of the fastest growing technologies in the world with a potential to surpass and replace cathode ray tubes (CRTs) in the foreseeable future. As a result of this growth, a large variety of FPDs exist, which range from very small virtual reality eye tools to large TV-on-the-wall displays.
Various types of displays exist, such displays utilizing both hot and cold cathodes that produce electrons that activate phosphor. Typically a hot source of electrons consists of a heated filament which causes thermionic emission of the electrons. Such a technique is well known to one of ordinary skill in the art, but has a number of disadvantages. For example, heating of the filament requires considerable power to be expended and represents a significant factor in the overall power required for the display. Furthermore, using a hot source of electrons makes fabrication of a large display difficult because the filament must be supported in a manner that will not be detrimental to cooling of the filament at its respective support locations. Furthermore, since the filament undergoes changes in its physical dimensions when heated, a structure capable of accommodating such a physical change is also required. This further adds to the difficulty and complexity associated with large display device fabrication.
Cold sources of electrons are typically achieved in a vacuum and may be formed in various configurations. Such configurations include spindt, nanotube, and electric field emission via low work function materials.
It would be desirable to obtain an emission source operable in conjunction with a TFT matrix to produce an efficient and relatively simple display device that requires less power and whose construction does not significantly limit the size of the display.